1. Field of the Invention
The present invention relates to a projecting device having plural bar lenses for projecting an image of an object a very short distance.
2. Description of the Prior Art
A compound lens system has been employed for example to reduce the size of a copier etc., and the use of bar lenses is for example disclosed in the U.S. patent application Ser. No. 889,404, (now abandoned) assigned to the assignee of the present application. In a compound bar lens system, two bar lenses are arranged along a common axis to constitute an element lens system for forming a part of the projected image corresponding to a part of the object. In the application of the compound bar lens system to a copier, the space between the element lens systems has to be shielded suitably against light passage, as otherwise the light passing through said space undesirably affects the electrostatic latent image formation on the photosensitive drum, leading to a flare formation on the developed image.
As the light-shielding means for the space between the element lens systems, the U.S. patent application Ser. No. 105,789 (now U.S. Pat. No. 4,275,962) of the present applicants discloses the use of a mask having holes of a pitch equal to the inter-axial distance of the element lens systems, provided at the entrance end of said element lens systems. However the preparation of holes at a pitch equal to that of the element lens systems tends to result in an elevated production cost of the mask. The present invention achieves the same result but with inexpensive means.